Building with block, and particularly concrete and cinder block, are types of construction well known to contractors, builders and masons.
Cinder block and concrete block are hollow-core block finding widespread use in building. This block is a well-known and conventionally used material for constructing the foundation and footings of a building. Hollow block construction is also a convenient and economical means for erecting building walls, particularly where the walls have windows and doors.
Concrete hollow block, also referred in the art as a concrete masonry unit, ("CMU") is supplied in a variety of sizes. The standard size and that most used is a block 8.times.8.times.16 (75/8.times.75/8.times.155/8) inches. This block is generally manufactured to have one, two or three cells or cores. The lateral dividing walls forming the core or cells of the block are sometimes called webs. While the standard width of the conventional block is 8 inches, blocks of 4, 6, 10 and 12 inch widths are available. The blocks or CMU's generally come in two external configurations: stretcher blocks which do not have finished ends, and corner blocks which have a finished corner (that is, two finished facing sides at right angles to one another).
There is a continuing need to improve the efficiency and strength of walls built of block. In using block construction, there is a tendency for the walls to be somewhat weak and for the joints to crack. Industry continuously seeks ways of improving the strength of structures where block is used.
One prior art product used for strengthening hollow block construction is a wire-mesh or grid called "Durowire"; others are Block mesh, Truss wire and Block wire. This product is designed to strengthen mortar joints between courses of block. In use, a course of block is laid and then mortar is enmeshed in the wire or grid. Then a second course of block is laid over the wire mesh and mortar of the first course of block. While this wire product supplies lateral strength, horizontally block to block, it does not supply substantial vertical strength between the vertical courses of adjacent block.
Unlike the wire mesh method, the method of this invention accomplishes adjacent vertical bonding between blocks, strength is increased and cracks in the mortar joints reduced.
Still another prior art method of block wall construction involves mortar poured directly into the hollows or cavities of the block to strengthen the wall. While this type of wall is strong, there are disadvantages. Firstly, this type of wall is costly to build due to the added mortar required to fill the entire cavity of the block. Secondly, there is a need to wait for the mortar between the joints of the block to set-up before mortar can be poured into the hollows. If pouring is done before set-up, the mortar poured into the hollows will force the still wet mortar out of the joints. It is clear that with the pour method, valuable time is lost because the steps of the pouring process are time-consuming.
A still further type of construction uses poured concrete walls rather than block. While the poured concrete method has the advantage of strength, it requires on-site forms; and it is not an efficient method of construction where doors and windows have to be placed in the wall.
The patent literature describes prior art showing various means and methods for reinforcing and strengthening construction in which hollow block is used.
Smith in U.S. Pat. No. 1,113,585 discloses a binder for hollow tile building blocks. The binder has slots through which cement flows to bind one row of block with the other. In addition to the slots, the binder is wide enough to catch and contain cement, thus preventing the cement from falling into the hollows of the blocks.
U.S. Pat. No. 1,297,151 to Griffin discloses a building block with notches for receiving reinforcing rods carried in the notches. A metal plate is fixed below the notches to receive cement which is retained therein to seal the rods in the notches.
A device for tile closure is taught by Scarth in U.S. Pat. No. 1,625,628. The device is designed to close the ends of tile used in building construction to prevent cement from entering the hollows of the block. This tile closure device is useful for sealing the hollows of tile block when cement is poured in areas adjacent to the block. The closure device thereby saves cement which would have been wasted during the pouring process.
Bingham in U.S. Pat. No. 2,325,653 teaches a wall construction system employing a spacer element placed between the rows or courses of block to prevent water seepage through the cement bonds between the rows of block. The spacer element also prevents cement from falling into the hollows of the block, thus saving cement.
In U.S. Pat. 2,776,559 Summers teaches the reinforcement of block wall construction by placing spacers between the courses of block along with reinforcing wire supported between the courses of brick.
None of the prior art patents discloses a contoured insert fitting between the courses of hollow block in such a way that mortar when poured into the hollow of a top block will internally, and within the cell, bind the top block to the bottom block.